The goal of the Harvard Center for Excellence to Promote a Healthier Workforce is to establish a sustainable trans-disciplinary program devoted to research, education, and dissemination that will facilitate the integration of occupational safety and health and workplace. The center will foster and expand collaborations with diverse employers, labor unions, and intermediary organizations to help shape the center's directions and to influence the dialogue among these constituencies regarding the application of integrated approaches to worker health. The leadership of this research team conducted the first research demonstrating the worker health benefits to be derived from integration of worksite health protection and health promotion. Building on solid institutional support, they have assembled an accomplished trans-disciplinary team with a track record of collaborative research, representing the diverse disciplines of occupational health and safety, social and behavioral sciences, social epidemiology, health education, medicine, economics, engineering, health communications, organizational behavior, nursing, law, and biostatistics. The center will initiate research in two high-priority employment sectors, construction and health care, aimed at addressing priority research questions across the full span of research phases. Integrated worker health research is a new to the health care sector, and accordingly, this study focuses on the early phases of research using social epidemiological methods, methods development, and preliminary intervention testing. Prior research in construction provides a firm foundation for full-scale testing in a randomized trial of an integrated respiratory health intervention aimed at silica exposure reduction and tobacco use cessation. A third project will train future and practicing professionals with a stake in worker health on skills and methods for integrating occupational health and safety and workplace health promotion, and will disseminate best practices and programs to key stakeholders and health professionals. In addition, strategically planned pilot projects will help to cultivate future research initiatives. This center application is aimed actualizing a vision for the integration of occupational health and safety and worksite health promotion that goes beyond the simple sum of the parts, to envision a new trans-disciplinary culture, science, and practice, operational in our work and providing a national model for future research, education and dissemination in support of worker health.